Flow in a Step-Wall Diffuser

AJ Baker, University of Tennessee, Knoxville

This example comes from the textbook "The Computational Engineering Sciences" by A.J. Baker.

Objectives of this problem:

1. Set-up COMSOL for GWSh solutions for the benchmark Navier-Stokes problem statement of flow in a step-wall diffuser for the DP + DM streamfunction-vorticity formulation.
2. Determine the primary recirculation region reattachment point on the lower wall for Reynolds number Re ranging 100 through 600. Adjust the problem domain span to ensure that the outflow vanishing derivative BC specification is appropriate for all Re.
3. Determine the meshing required to generate engineering accurate solutions at Re = 100 and Re = 600.
4. Compare your GWSh solutions to the available experimental data and comment on the distinctions.

User Comments

James Freels
Aug 2, 2009 at 3:17pm UTC

This is an alternative solution using COMSOL (alternative to the examples in the model library) for the classic step-wall diffuser problem. In my opinion, what sets this model apart from most is the excellent example of using the COMSOL-unique feature of modeling your own equation system using the PDE formulation capability. And what a powerful example indeed by demonstrating how to solve the streamfunction-vorticity formulation of the Navier-Stokes equations. A natural extension to this example would be to solve the problem in 3D. It would also be great to have an actual reference for the experimental data for verification and quality assurance. Thank you AJ for providing this model exchange.